Improvement in acoustic telephones



UNITED STATES PATENT OEETGE.

JAMES DRAPER, 0F VORCESTER, MASSACHUSETTS.

IMPROVEMENT lN ACOUSTiC TELEPHONES.

Specilication forming part of Letters Patent N0. 213,813, dated April l, 1879; application iiled January 1G, 1879.

To all whom it may concern:

Be it known that I, JAMEs DRAPER, ot the city and county ot' Vorcester, and Gommonwealth of Massachusetts, have invented certain new and useful Improvements in Acoustic Telephones; and l do hereby declarcthat the following is a i'ull, clear, and exa-ct description oi' the sinne, reference being had to the accompanying drawings, forming a part of this specification, and in which- Figure l represents a side View of a pair of my said improved acoustic telephones secured to their respective walls or partitions, as will be hereinafter more fully described. Fig. 2 represents a central longitudinal section of the parts shown in Fig. l, taken on line A B of the saine figure. Fig. 3 represents a transverse section 'through one oi' the telephones, taken on line A B', Fig. 2, looking in the direction indicated by arrowin the same figure, and Fig. l represents a portion of the device, hereinafter incre fully described.

To enable those skilled in the art to which my invention belongs to make and use the same, I will proceed to describe it more in detail.

In the drawings, the parts marked C represent sections of walls or partitions upon which 'the telephones D D are arranged and secured. Said telephones D D are constructed with trumpet-shaped mouth-pieces E E and the parts F F', which are secured to walls or partitions C by means of screws a.

The parts F Fl are formed with sockets, into which fitted the ends of mouth-pieces E E', and secured in position by means of setscrews l) or otherwise, as may be desired.

Both the mouth as well as socket pieces E E and F F are cored out, as represented at c d, for the purpose of forming concentrating soundingchainbers Gr G", the diaphragme being supported so as to divide said soundcoucentra-tin g chambers, as fully indicated in the drawings.

Betwe i flanges e c of mcutlrpieccs E E and shoulders or bearings ff of parts F F are secured said diaphragme H H', which are composed in this instance of thin metallic plates, although any other suitable yibrative material may be used, if preferred.

To the centers of diaphragms H H are se cured the ends of the conducting wire or line connecting the two telephones, as is also indicated in the drawings.

By formi ng the mouth-pieces E E with large outer openings, and tapering them down toy small openings at their inner ends, as represented by full and dotted lines in the drawings, sounds entering and passing through the same are concentrated upon the centers ot diaphragms H H', where the conducting wires or lines are secured, as before stated, and said sounds transmitted over the latter with such force and distinetness that by speaking into one of the telephones the voice is reproduced upon the diaphragm of the other, when placed 0r secured at a considerable distance, with `such distinetness that each word is clearly and plainly distinguishable.

The peculiar form of chambers Gr G contributes to the success ofthe operation ofthe device in obtaining the last-before mentioned results, since by making the inner ends of mouthpieces E E of spherical form c they act as sound-concentrating chambers to detlect the air vibrations upon the centers of the diaphragms H H.

'The vibrations of the sound or the vibrations ofthe air occasioned by the voice of the operator,being concentrated upon the centers ot' the diaphragms, are communicated in a steady and stron g mann er to the conducting-wire, and are delivered in the sa-me way.

Annular spherical surfaces d also serve the same purpose as surfaces c, there being spaces left between the projections g g and the een ters ot the diaphragms, as fully indicated in the drawings 5 and, ii' preferred, the projections g g may be reduced to thin circular edges, instead of being shown blunt, as shown in the drawings.

rihe mouth-pieces it will be observed, are so ttcd as to hohl the outer edges of the diaphragms iirin, secure, and tight against the shoulders j' j", thereby preventing the air escaping or passing from one chamber to the other around the outer edges ot' said diaphragms H H.

in the use of my acoustic telephones it important to keep the conducting wire or line l from contact with metal and other rigid sur faces, and itis also important to keep it pretty angle, as indicated in Figs. 2

taut 5 and to accomplish the purposes lastabove described I employ a supporting-spring, J, in combination with a rubber elastic guidepiece, K, through which the wire passes when it is desired to turn the conducting-wire at an and 4 of `the drawings, the latter drawing indicating in full lines how the wire can be deiiected or turned in either direction.

The elastic rubber piece Kprevents the vibration of the conducting-wire I from being disturbed or impaired by the metal yspring J, while the latter, contracting and yielding, keeps the conducting-wire in proper tension, and that, too, without endangering its being broken from any overstrainin g cause.

To prevent conducting-wire I and the end of spring J being torn out of the openings formed in rubberpiece K, eyelets 7c are secured in said openings, which also allows the conducting-wire to slip through the same more easily. Said piece K may be made rectangu lar in shape, as represented in the drawings, or any other desired form. It may also be made of any other material which is a nonconductor of sound-vibrations. A

By the use of the eyelet 7c the conductingwire can slip or move easily; consequently its vibrations are not disturbed nor broken, which would be the case if it were allowed to embed itself in any soft yielding substance, such as rubber or other similar material.

If desired, `felting or some other soft material may be placed around the conducting wire I, where it passes through walls or partitions C, for the purpose of preventing said Wire from coming in contact with the former. This precaution is lnore especially desirable when the conducting-Wire is arranged upon an angle, as before stated.

Having described my improved acoustic telephone, what I claim therein as new and of my invention, and desire to secure by Letters Patent, is y l. The combination, with the diaphragmsH H and conducting-wire I, of sound concentrating chambers G G', formed by the concavities c and d in the mouth and socket pieces, of spheroidal and annular shape, as shown, and for the purposes set forth.

2. The combination, with the telephonie conducting-wire I, of a rubber supporting-piece, K, provided with a hard smooth eyelet, k, sub-` stantially as and for the purposes set forth.

3. The combination, with the telephonie wire I, of a rubber supporting-piece, K, and elastic spring J, substantially as and for the purposes set forth.

JAMES DRAIER.'

Witnesses EDWIN E. Moonn, ALBERT A. BARKER. 

